System for converting a liquefied gas into vapor



Nov. 21, 1944- A. Buss ET. AL 2,362,963

SYSTEM FOR CONVERTING A LIQUEFIED' GAS INTO VAPOR Filed July 8, 1941 4 Sheets-Sheet 1 k INVENTOR Nov'. 21, 1944. L A. BLISS ETAL 2,352,963

SYSTEM FOR CONVERTING A LIQUEFiED GAS INTO V APOR Filed Jilly s', 1941 -,4 Sheets-Sheet 2 Q l, i.

Z INVENTOR$ BY, 'WM/g Nov. 21, 1944.

L. A. BLISS -E-Tl' AL SYSTEM FOR CONVERTING A LIQUEFTED GAS INTO VAPOR 4 Sheets-Sheet 3 Filed July 8, 1941 Nov. 21, 1944. L A. BLISS ETAL 2,352,968

$Y$TEM 'FO R CONVERTING A LIQUEFIED GAS INTO VAPOR Filed July 8,-1941 4 Sheets-Sheet 4 5 Q I x INVENTOR Patented Nov. 21, 1944 SYSTEM FOR CONVERTING A LIQUEFIED GAS INTO VAPOR Lyman A. Bliss, New York, and Odd A. Hansen, Kenmore, N. Y., assignors to The Linde Air Products Company, New York, N. Y., a corporation of Ohio Application July 8, 1941, Serial No. 401,460 23 Claims. (01. 62-1) This invention relates to a system for converting a liquefled gas into a vapor or industrial use, and more particularly to a system adapted to be installed at a consuming plant for storing and converting liquid oxygen into gaseous oxygen whenever desired.

The invention has for its object generally the provision of an improved construction and arrangement of component devices for quickly and expeditiously converting a quantity of liquefied gas, such as liquid oxygen, into gaseous material at a relatively high pressure.

More specifically, the invention has for its obiect the provision of an improved system for storing and converting liquid oxygen into gaseous oxygen ata relatively high pressure, while at the same time maintaining the storing device at a rel atively low pressure.

Another object is to provide a system of the character indicated with transfer pumps so located with respect to the liquid storing device as to efiect the transfer of liquid to and from the same, when desired, in a relatively short space of time. Another object is to.provide a system of the character indicated with storage means of relatively large capacity and relatively small losses and arranged with respect to the other devices in the system in a manner which permits charging the same with relatively large amounts of liquid and at relatively infrequent intervals if feasible.

Another object is to'provide a system of the character indicated with means connected thereto in a manner which incorporates a reservoir for oxygen either in the liquid phase or in the gas phase at high pressure, in order that a response may be had substantially instantaneously to demands for oxygen. The reservoir when provided with a connection into the system as disclosed so that it' is in constant fluid communication therewith may be said tobe floatingly I /plifled in the construction hereinafter set forth,

' Still another object of the invention is to pro- I and the scope of the invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention reference should be had to the following detailed description taken in connection with the accompanying drawings, in

which: I

Fig. 1 is a. view, partly in section and partly in elevation, showing a system having floating means for holding liquid oxygen and adapted for intermittently dispensing'oxygenin accordance with the invention;

Fig. 2 is a similar view showing a modified type of system having floating liquid holding means provided in accordance with the invention;

Fig. 3 is a similar view showing another modified system having floating. gas holding means car. Such storage container is preferably of relatively large capacity and has a liquid'supply and withdrawal connection l2 communicating with a point closely adjacent to or at the bottom of vessel Ill. The connection I2 is shown as controlled by a pair of valves l2 and I2" and leading from the outlet of a transfer pump I3 which is preferably disposed below the storage container and has an inlet connection N that terminates in a coupling l5 to which a service connection leading from a transport container (not shown in the drawings in the interests of clearness of illustration) is adapted tobe attached. Associated with the connection I! there is a branch I21: that is valvecontrolled and is adapted tobe coupled by another connection that leads to the gas space of the transport container for priming purposes. A connection I2 controlled by a valve l2 and leading to the top of vessel l0, may be provided when desired.

Liquid withdrawal from the storage container, as well as liquid introduction, may be advantageously accomplished through the connection l2. Accordingly, it is shown tapped by a connection l8 having a'valve l8 and leading to the inlet of a pipeline pump l'l.

, Both pumps 13 and I1 in this embodiment or the invention are preferably of the rotary type.

The pump at I3 is required to pump only against a head of pressure which is substantially a grav-' which issued February 1, 1944, as Patent No.

A discharge conduit l8 having therein an automatic priming valve l9 leads from the outlet of pump I1 through a portion 18' to the gas space of the vessel ID. A conduit 20, having therein a check valve 2|, is tapped into the conduit l8 at a point preferably in advance of valve 19. A control valve, as shown at 2|, is also preferably introduced in the conduit l8 for the purposeof adjusting the time response of valve l9. Such valve can be so set that valve 18 is responsive to the pressure in conduit 18 and causes valve 19 to close a short time after the pump I1 is started. Thus when pump 11 is idle and for a brief interval after it has started, valve 19 opens and the pump primes by recirculation back to container ID by way of branch l8. As soon as liquid passage is established, the pressure rise in conduit 18 causes valve [9 to close and the discharge from pump 11 must thereafter pass out by way of conduit ZU-through check valve 2|.

' The conduit 20 is preferably branched as shown at 22 and 22' which lead in parallel to a depending portion 221: that feeds into an auxiliary container 24 at the top. Branch 22 has therein a heating coil 23 while branch 22' has a back pres- ,surevalve 25 normally closed but arranged to open upon the attainment of a predetermined high pressure in the container 24 so as to permit the discharge of cold liquid along with heated material directly into the container 24 and thereby reduce the pressure therein. Such container is advantageously constructed with a materially less capacity than the container l I.

The liquid, when introduced into the container 24 as here proposed, is substantially a saturated liquid at a relatively high pressure. Such'liquid is arranged to be withdrawn when desired from the auxiliary container and supplied to suitable Vaporizers. To this end, a connection 26 that leads from a; point relatively close to the bottoms of container 24 is provided and leads to a second'heating coil 21. A gas phase connection 28 is also preferably provided and arranged to lead from the gas space of the auxiliary container into a third heating coil 29. The coils 23, 21,

and 29 are supplied with suitable heating medium, either. separately or collectively. A common heater casing for the purpose of heating them collectively is indicated in the drawing at H.

The outlets from coils 21 and- 29 lead to a common service main 30 which has a regulating .manifold 31, or equivalent device, connected therein, and is arranged to lead into a metering device, here symbolically indicated at 32. Any

suitable metering device may be employed, for example, a conventional bellows meter.

The connection from coil 29 to the main 30 is provided with a back pressure valve 33 which 50 of the pressure regulator at 3|.

is arranged to open when the pressure in con tainer 24 reaches a predetermined high value in order to efiect preferential withdrawal of gas phase from the container 24 and thereby reduce '5f the pressure therein. Whenthe valve 33 closes,

only liquid phase is withdrawn, by way of conduit 26, from the container 24.

The liquid level in the auxiliary container is preferably maintained between fixed limits and the maintenance advantageously accomplished automatically. The level indicating conduit 34 is accordingly provided with a liquid level controlled switch, shown diagrammatically at 35,-

which is connected through an electrical circuit shown diagrammatically at l1a to control the motor (not shown) that runs pump 11. By such arrangement the pump I1 may be started automatically whenever the liquid level in the auxiliary container falls below a desired point,

and automatically stopped when the liquid level reaches a desired point. A safety valve '36, disposed at a convenient point, for example in communication with connection 1 28, operates to maintain thegas pressure in the container 24 at a desired value.

In operation, the system above described normally has gas under pressure substantially above atmospheric in the gas spaces of both containers H and 24. The pressure in container II is preferably only slightly above atmospheric, for example, 15 p. s. i. gauge. The pressure normally obtaining in container 24 is maintained at a value substantially above that in the pipeline, for example, 25 p. s. i. above that of the pipeline.

The pressure in container 24 is, however, normally of a relatively low value, for example, 150 p. s. i. gauge. The pressure in the pipeline is normally of a value of from 100 to 125 p. s. 1. gauge. The pressure in container 24 40 may rise to a relatively high value at times, due

to heat leakage, for example, to a value of 400 p. s. i. gauge. This permits heat storage over an extended period without'loss of gas phase through the safety valve 36. Such pressure is, of course, reduced as soon as withdrawaloccurs, mainly that which takes place through conduit 28. The pressure of the gas in the service main is normally maintained at a constant pressure, for example, 100 p. s. 1. gauge, due to the action In. the event thereis a demand for gas made on the service main, theregulator opens and gaseous oxygen flows from the coils in heater H to meet the demand. The gas pressure inthe auxiliary con- -.tainer causes liquid to flow through the connection 26 into coil 21, while gas flows through the connection 28 into coil 29 as soon as pressure in the container is high enough to keep valve 33 open. If the demand continues, or if repeated until the'level of the liquid in container 24 falls introduced therein through the conduit 22 and the depending connection 221:.

The gas material enterin the container 24 by way of conduit 22 and connection 222: is in the vapor, phase, since it has traversed the heating 7 coil 23. This in turn produces a pressure rise in container 24 until the valve 25 opens. Gas material in liquid phase now enters container 24 by way of conduit 22' which branches off from the conduit 22 in advance of the heating coil 23.

The material in the liquid phase thus supplied valve 25 automatically closes.

aseaoes is substantially at the pressure in the container 24 but by reason 01! its lower temperature causes condensation of vapor in container 24 which tends to reducethe pressure therein. When the pressure in container 24 has sufllciently dropped An increase in the flow of material entering by way of coil 23 and conduit 22 now takes place and continues until a'balance is achieved.

The check valve 2I in the connecting conduit 20 operates not only to pass readily the liquid being transferred by pump I1, but also to prevent the pressure values that obtain in the auxiliary container andithe circuit 22 from building up in the connection to, or in, the gas space of container II. In this way, a relatively low pressure is at all times maintained in the container II, i. e., a pressure not in excess of 15 p. s. 1. gauge, as above described.

The auxiliary container 24 is thus seen to be in constant communication with the supply line which may be considered as leading'from connecting conduit 20. If this auxiliary container were-made relatively large, such portion of the system from the auxiliary container on would be but a system of the kind commonly referred to as a cold converter system and disclosed in U. S. Patents Nos. 1,942,944 and 1,943,047, issued respectively in the names of Smith and Updeg'raii OnJanuary 9, 1934. By this attachment, there is always a suificient supply of gas mateterial maintained inreserve to meet instaneous oxygen, suchgas occur in. industrial plants, particularly in. metal working plants. That this is so will be readily understood when it is noted that the liquid material in the auxiliary container is both at high pressure and nearly boiling.

When a charge of liquid is introduced into the container II, supplied from a transport container that is shipped open to the atmosphere, a partial reduction of the pressure in container II takes place. During the periods when withdrawal of liquid phase from the container II takes place, the pressure therein is allowed to rise as this avoids loss of gas phase to the atmosphere on account of heat leakage. Each subsequent filling of container -II effects a similar lowering of the pressure therein The economies obtained by this system are taneously the relatively large demands for gasseen to be due to the fact that the large body of liquefied gas, such as is necessarily maintained at the plant in the container II in order to meet relatively large demands, is not at high pressure divided insulating material in the insulating space which is evacuated as taught in the copending application, Serial No. 307,945, filed in the name of L. I. Dana on December 7, 1939.

In the modification shown inFig. 2, the container II is indicated asarranged substantially in the same manner win the system of Fig. 1. The pump connections, however, are different, the arrangement being of a character adapted for relatively continuous operation of the pumps. Such operation is adapted to loads with less violent fluctuations than occur in systems ordinarily serviced by the arrangement of Fig. 1.

Here the connection I20, which leads from the 'bottom of vessel I0 in container II, serves only as a liquid withdrawal connection. This connection has a control valve I2 andleads into conduit I4 that terminates with coupling I5. This latter, as in the system of Fig.' 1, is adapted to be connected through a flexible hose to receive a charge from a transport container. A valve I4 controls conduit I4. Hence it is seen that the conduit I20 and conduit I4 lead in parallel to an inlet I3I of a first-stage pump I30. Anoutlet connection I6I leads from the pump I to a conduit I62 and has a branch I63 leading to the inlet of a second-stage pump I10. An outlet conduit I80 leads from pump I10 and communicates at its upper end with the gas space of vessel I0. Conduit I80 is controlled by a valve I8I and has a connecting conduit 200, leading from a point between the outlet from pump I10 and valve IOI to the supply circuit 22.

Conduit 200 has valves MI and 202 to control it, the latter being a check valve. By the arrangement provided, it is seen that the pumps I30 and I10 operate in series. Pump I10 may, therefore, be a single-stage'pump as well as that at I30. This series operation takes place except when liquid is introduced to container .II; one such pump being sufiicient for this service.

One end of conduit I62 connects with and discharges into conduit I80 at a point between the container I0 and valve I8I. The portion of conduit I62 which so connects with conduit I80'is controlled by a valve I62. The other portion of conduit I62 that leads from the conduit I 6| in theopposite direction to that having valve I62 is also provided with a valve I62" and is terminated with a coupling I to which a flexible connection leading to .the gas space of a transport container may be attached. By such connections the gas evolved from both pumps I30 and I10, when being primed, is adapted to be conveyed to the gas space of vessel I0. Vessel I0, which is normally intended for closed operation, is accordingly provided with a safety valve I00.

The supply circuit 22 has an associated auxiliary container 24, together with heating and vaporizing coils, arranged substantially as shown in the system of Fig. 1. Here no automatic pump control is provided, as the auxiliary container may be relatively large and hand control of the pumps I30 and I10 relied upon. In efiecting such control, the pumps however are started and stopped substantially simultaneously. Since the container II is here operated -under pressure, the upper limit' of which is maintained bythe safety valve I00, the priming of the pumps need not be provided for other than initially. Hence the priming valves I62, I 8I and I82 are preferably manually operated valves, although such ed, andthe charge supplied through connection I4 (valve -I4' having been opened while that at I2 is closed) is then passed successively through the pumps I30 and I10 and discharged at a desired pressure into the vessel I at the top.- The priming of the pumps may be necessary for 'filling, if this operation is to take place at the end of a time when the pumps have stood idle for a relatively long interval. For, this purpose, valves I62, I62" and [BI may be temporarily opened and valve I82 closed. As soon as liquid begins to pass valves I62 and I62" are again accordingly one adapted to pump against such.

high head. To this end the liquid pump for transferring the liquid from the liquid storage container, such as shown at II, is a reciprocating pump arranged to force liquid against such pressure. A suitable reciprocating pump adapted for this service is shownin copending application, Serial No. 369,023, filed December 7, 1940, in the name of O. A. Hansen. The arrangement utilizing such pump illustrated in Fig. 3, while shown as used in a stationary installation, is also adapted to bemounted on a truck or vehicle for transport service? Here inner vessel III has a spaced outer vessel I I that encloses an insulating space, as above described. A liquid inlet and withdrawal connection is provided at I2 and has a control valve I2. Such connection leads from the outlet of a low pressure liquid transfer pump I3, which I again is preferably of the rotary type and ar-' ranged as in Fig. 1. A valve controlled branch withdrawal line I2b also leads from the line I2 to the inlet of pump I3 which is utilized when pump I3 is employed as a fore pump supplying liquid to the second stag pump I15. Aconnection I22: controlled by a valve I2" is also provided adapted to be connected, if desired, to the gas spaceof the transport container for primin purposes.

From the outlet of pump I3, a discharge conduit I6 (having a control valve I6) leads to the inlet of a reciprocating high pressure second-stage pump, here denoted I15. The discharge from this latter pump passes through conduit I35 and then into a connecting conduit 220 that leads to a vaporizing coile'223. This latter has an outlet conduit 221 that leads to a bank of gas phase receivers 224 that are floatingly .attached, that is, they are in constant communication with conduit 22! and serve as accumulators or supply reservoirs, dependent upon conditions of demand and supply. A branch conduit 222 leads to a service main through a regulating manifold, as shown at 3|, and a meterin device, as shown at 32. A pressure controlled switch 300 for automatically starting and stopping the motor I16 which actuates pump I15 is provided in communication with conduit 222, the electrical connection from switch 300 to the motor I16 bein shown generally at I16a.

The connection I85 is arranged to lead to the gas space of vessel I0 and has therein an automatic priming valve I86. Such valve is preferably automatic, as above described, or may 'be electromagnetically actuated; a solenoid for such purpose being shown at I86. This valve is hence aaeaeee automatically opened when the pump I15 starts and closes when liquid begins to pass. The gas discharged by the pump I15 when being primed discharges into a closed space, i. e., the gas space of vessel I0, an excessive pressure therein being prevented by means of a safety valve I00. A by-pass having a control valve I84 may be provided for manually priming the pump, if desired.

In the modification shown in Fig. 4, an arrangement is employed which is substantially a cold converter system of relatively high capacity and adapted to service loads that make relatively great demands and require substantially instantaneous response- Transfer pumps of both low pressure and high pressure types are incorporated at points wheremcaclerated liquid how is required, also gas pumps may be used.

In the arrangement an inner vessel I0 is surrounded by a vessel II, which is spaced therefrom for insulating purposes. The vessel 20' here provided is designed to withstand relatively high pressures, and has a liquid filling and withdrawal connection I2, provided with valves I2 and I2" therein and attached to the outlet of a transfer pump 13. The latter has an inlet connection I4 terminating with a coupling I5 for receiving a liquid charge that is to be transferred to the vessel I0. A priming connection I211: is also provided, as in Fig. 1. Communicating with connection I2 is another connection I6 having a. valve I6 and leading to the inlet of a high pressure liquid transfer pump I11 which is preferably of the reciprocatin type, like the pump I15, above described. Such pump is arranged substantially as in Fig. 3 and has an actuating motor I18. Here a discharge conduit I81 leads fromthe outlet of pump I 11 and discharges into vaporizing coils 221 and 221' that discharge in a supply main 230-. This main has a bank of gas receiving vessels 224 floatingly attached and a connection 222 leading to a service main through a regulating manifold M and a metering device 32, as in the other modifications. An automatic control for pump I11 is also preferably provided and here comprises a pressure controlled switch 300 and priming valve 590, as in Fig. 3. The latter is arranged to control a priming connection I88 that leads to container II. A connection I89 also leads from the gas space of container I I to a heating coil. 229 which is arranged to discharge into the inlet of a suitable gas pump 240, which discharges into the supply main 230; a carbon ring pump, such as disclosed in copending application, Serial No. 409.626. filed September 5, 1941, in the name of G. J. Boshkoff, being an example of asuitable gas pump. An automatic by-pass valve 2M about the pump is advantageouslyprovided.

Here vessel I0 in container II is a relatively thick-walled or pressure vessel. Hence the liquid therein may be and-normally is under considerable pressure in order that liquid may be withdrawn and supplied to the pump I11 under a pressure sufficient to impart a desired degree of subcooling. To this end, provision is made for quickly vaporizing a desired amount of liquid to suoply the pressure without at the same time unduly heating the liquid in the vessel I0. According. a liquid withdrawal and heating connection is provided, which, in this instance, preferably includes aliquid transfer pump, which because of its low pressure service may Well be a rotary pump. This is here indicated at 2I0 disfor holding a reserve of said gas material under posed in a conduit circuit 2 that has one end leading from the bottom of vessel l into the pump H0. The other end'portion leads from the discharge of the pump 2H] into the gas space of I vessel and includes a vaporizing coil 2l2. In this arrangement, the pump 2H1 is normally primed at all times and when started withdraws liquid from the vessel l0 and the liquid is vaporized in coil 2I2. In this manner, a pressure of desired value, limited of course by safety valve I 00, obtains in the vessel 10'. It is preferable, however, to associate with the system another pressure controlled switch responsive to the pres sure in vessel III for actuatin gas pump 240. This is here shown at 250 attached to conduit The switch 250, which controlsthe gas phase pump 240, is arranged to start pump 240 operating through the electrical connection 240a whenever the pressure in vessel l0 exceeds a predetermined value (less than that for which safety valve I00 is set). Pump 24!) then operates to compress the gas and transfer it from vessel l0 to the supply conduit 230, the gas pump being automatically stopped when the pressure in vessel l0 falls to a predetermined low value.

In the event the pressure in vessel ill tends to fall to a still lower value, then it is advantageous to provide still another automatic, pressure responsive controlling switch'which may be connected to the motor of pump 210. The switch means is here indicated at 260 connected to fluid circuit 2| I, an electrical connection for control- I same when this value is attained.

The reserve of gas material in the receivers 224 is, of course, maintained by the pump IT! which is automatically controlled by the switch at 300 connected through electrical circuit 8a with the rotor I18. Thus the system here provided is seen to be pipeline demand controlled, since the pressure which actuatesthe switch at 300 is subject to the fluctuations oi the pipeline pressure,

Details .of switches and circuits for effecting the above controls are here omitted, as any suitable system. thereof known to the prior art may be employed. A suitable arrangement, however, is described in the copending application of G. J. Boshkoff, supra.

Since certain changes may be made in the above construction and'different embodiments of the invention could be made without departing from the' scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted asillustrative and'not in a limiting sense.

Having described our invention, what we claim as new and desire to secure by Letters Patentis:

1. In a system for converting a liquefied gas *into a vapor for industrial use, the combination pressure in fluid communication with said consuming system, and means for maintaining a desired pressure in said reserve holding means.

2. In a system for converting a liquefied gas into a vapor for industrial use, the combination with a heat insulated container adapted for holding a supply of said liquefied gas, of pumping means associated with said container and having liquid phase connections leading therefrom, a gas consuming system including servicing connections and heating and vaporizing means connected to be supplied through said pumping means, means for holding a reserve of said gas material under pressure in fluid communication with said consuming system, and means for controlling the operation of said pumping means liquid phase connections leading therefrom, a gas consuming system including servicingconnections and heating and vaporizing means connected to be supplied through said pumping means, means for holding a reserve of said gas material under pressure connectedto said system, means for regulating the pressure in said system, and means for automaticallyoperating said liquid pumping means for maintaining a desired reserve in said reserve holding means.

4. In a system for converting a liquefied gas into a vapor for industrial use, the combination with a heat insulated container adapted for holding a supply of said liquefied gas, of pumping means associated with said container and having liquid phase connections leading. therefrom, a gas consuming system including servicing connections and heating and vaporizing means connected to be supplied through said pumping means, an auxiliary container for holding a reserve of gas material in both liquid and gas phases under pressure connected to said con into a vapor for industrial use, the combination with a heat insulated container adapted for holding a supply of said liquefied gas, of pumping means associated with said container and having liquid phase connections leading therefrom, a gas consuming system including servicing connections and heating and vaporizing means connected to. be supplied through said pumping means, an auxiliary container connected to said consuming system for holding a reserve of said gas material in both liquid and gas phases under pressure, and means for effecting preferential with'drawalof gas phase from said auxiliary container when a predetermined pressure is exceeded.

6. In a system for converting a liquefied gas into a vapor for industrial use, the combination with a heat insulated container adapted for holding a supply of said liquefied gas, of pumping means associated with said container and having gas consuming system including servicing conliquid phase connections leading therefrom, a gas consuming system including servicing connections and heating and vaporizing means connected to be supplied through said pumping means, an auxiliary container in fluid communication with said consuming system for. holding a tion with a heat insulated container adapted for holding asupply of-said liquefied gas, of pump--* in v means associated with said container and having liquidphase connections leading therefrom, a gas consuming system including servicing connections and heating and vaporizing means connected to be supplied through said pumping means, an auxiliary container connected to said consuming system and adapted for holding a reserve of said gas material in both liquid and gas phases under pressure, and float actuated means connected to said auxiliary container for automatically operating said pumping means whereby the level of the liquid in said auxiliary container may be maintained.

8. In a system for converting a liquefied gas into a vapor for industrial use, the combination with a heat insulated container adapted for holding a supply of said liquefied gas, of pumping. means associated with said container and having connections leading thereto for transferring liquid into and withdrawing the same from said container, a gas consuming system including distributing conduits and interposed heating and heating and vaporizing means connected to receive liquid phase withdrawn from said container, an auxiliary container, branched connections leading from said system to the gas space of said auxiliary container, one of said branches being adapted to supply liquid from said pumping means to said auxiliary container and efiect a partial condensation of the gas phase therein, said other branch being provided with automatic regulating means whereby a preferential withdrawal of gas phase is effected and supplied to said system, means for withdrawing liquid from said auxiliary container upon demand in said system, means for regulating pressure of the gas phase 'supply in said system, and means for operating said pumping means for maintaining a desired reserve in said auxiliary container.

11. In a system for converting a liquefied gas into a vapor for industrial use, the combination with a heat insulated container adapted for holding a supply of said liquefied gas, said container having a relatively heavy-walled inner vessel, of a gas consuming system including service connections and heating and vaporiiing means connected to be supplied from said container, pressure building means including a heating coil connected to said heavy-walled vessel at pointsboth above and below the normal liquid level therein, pumping-means associated with said pressure building means and arranged to withdraw liquid from said container and accelerate the rate of pressure-building, and pressure responsive means vaporizing'means connected to said container,

means for holding a reserve of said gas material under pressure in continuous communication with said consuming system, and means for automatically operating the liquid withdrawal pumping means for maintaining a desired reserve in said reserve holding means. '9. In a system for converting a liquefied'gas into a vapor for industrial use, the combination with a heat insulated container adapted for hold ing a supply 01 said liquefied gas, of pumping means associated with said container and having connections leading thereto for transferring liquid into and withdrawing the same from said container, a gas consuming system including distributing conduits and interposed heating and vaporizing means connected to said container, an auxiliary container connected to said system for V holding a reserve 0! gas material in'bothliquid and gas phases under pressure, means for regulating the pressure otsaid system,- means for efiecting preferential withdrawal of gas phase from said auxiliary container when a predetermined pressure is exceeded therein, and liquid level actuated means associated with said auxiliary container for automatically operating the liquid withdrawal pumping means whereby a desired reserve of material in th liquid phase-is maintained in said auxiliary container. i

10. In a system for converting .a liquefied gas into a vapor for industrial use, the combination with a heat insulated container adapted for holding a supply of said liquefied gas, of pumping means associated with said container and having connections leading thereto for trans-- rel-ring liquid mm and withdrawing the same from said. container, 9. gas consuming system infor controlling the operation of said pumping means.

12. ,In-a system for converting a liquefied gas into a vapor for industrial use, the combination with a heat insulated container adapted for holding a supply of said liquefied gas, said container having a relatively heavy-walled inner vessel, of a pressure building means associated with said container and having a vaporizing means therein, a liquidrpump associated with said pressure building 'means for accelerating the action thereof, additional pumping means associated with said container and having connections for withdrawing liquid therefrom, a gas consuming system including servicing connections and interposed heating and vaporizing means connected to said additional pumping means, and automatic me ans for controlling said additional pumping means in response to a condition in said consuming system; v

13. In asystem for storing and converting a liquefied .gas into vapor for industrial use, a main heat insulated liquid storage container, a gas consuming system embodying servicing connections, heating and vaporizing means, and auxiliary storage means, pumping means and fluid conduits for delivering liquid from said main container to said consuming system, and means for controlling the operation of said pumpin means to maintain a desired minimum pressure insaid auxiliary-storage means.

eluding distributing conduits and int rp sed, 7

14'. In a system for storing and converting a liquefied gas into a vapor for industrial use, a heat insulated main storage container for holding a supply of said liquefied gas adapted to be maintained. at'ajrelatively low pressure, a gas consuming system embodying servicing connections and vaporizing and heating means, pumping means and fluid conduits for supplying gas material from said container to said consuming system at increased pressure, means for holding a reserve of the gas material under pressure connected with said consuming system, and

means for automatically controlling said pumping means to maintain a desired pressure in said reserve holding means above that of said main container.

15. In a system for storing and dispensing a liquefied gas and converting it into vapor for industrial use, a main heat insulated liquid container adapted to be maintained at a relatively low pressure, an auxiliary smaller liquid container, fiuid conduits and pumping means for delivering liquid from said main container to said auxiliary container at higher pressure;

a boiling point temperature at atmospheric pressure below 273 K., a storage container for the liquid, a pump for delivering the liquid under such pressure for use having an intake connected to said storage container, a main delivery line for said pump, an auxiliary discharge line connected to said pump and leading to a pointof relatively low pressure with respect to the normal delivery pressure of said pump, an automatically operable valve in said auxiliary discharge line responsive'to pressure therein, said valve being constructed and arranged to be open upon vaporizing and heating means connected with for gas consumption apparatus, fluid conduits and pumping means for delivering liquid from said main container to said auxiliary container, servicing connections for supplying consumption apparatus, means for efiecting preferential withdrawal of gas phase from said auxiliary container for use when a predetermined pressure is exceeded, means for controlling the operation of said pumping means to maintain a predetermined quantity of liquid in said auxiliary container, and vaporizingand-heating means connected with said auxiliary container and servicing connections.

liquefied gas into a vapor for industrial use, the combination with a heat insulated container adapted. for holding a supply of said liquefied gas, of a gas consuming system including servicing connections and vaporizing and heating means connected to be supplied from said container, pumping means for delivering liquid from said container to said consuming system, gas receiver means in fiuid communication with said system adapted to hold a reserve of gas .under pressure suificiently high for the consumption apparatus to be supplied, and means responsive to the pressure in said system for controlling the operation of said pumping means to maintain such pressure above a predetermined value.

18. Ina system for storing and converting a liquefied gas into a vapor for industrial use, the combination with a heat insulated container initial starting. of said pump during generation of substantial quantities of gas from the liquid while said pump is being cooled by the material passing therethrough and to close by the development of a predetermined pressure in the pump discharge.

20. In a system for supplying under pressure a highly volatile liquefied gas material having a boiling point temperature at atmospheric pres-.

sure below 273 K., a source of supply of such liquid, a pump for delivering the liquid under such pressure for use having an intake connected to said source of supply, a main delivery line for said pump, a check valve therein preventing back fiow, an auxiliary discharge line connected to said pump in advance of said check valve and 1'7. In a system for storing and converting a adapted for. holding a supply of said liquefied gas, of a gas consuming system including servicing connections and vaporizing and heating means connected to be supplied from said container, pumping means for delivering liquid from for the consumption apparatus to be supplied,

and means responsive tothe pressure in said 'system for controlling the operation of said Dumping' .meansto maintain such pressure above a predeterminedvalue.

19. In asystem for supplying under pressure a highly volatile liquefied gas material havin leading to a point of relatively low pressure with respect to the normal delivery pressure of said pump, an automatically operable valve in said auxiliary discharge line responsive to pressure in the pump discharge, said valve being constructed and arranged to close when substantial pressure is developed by the passage of liquid into the auxiliary discharge line causing the pump to deliver the liquid to said main delivery line and to remain open when no liquid is being delivered by said pump.

21. In a system for storing and converting a liquefied gas into a vapor for industrial use, a heat insulated storage container for holding a supply of said liquefied gas, a gas consuming system embodying servicing connections and vaporizing and heating means, pumping means and fluid conduits for delivering liquid from said container to said system, pressure regulating means in said servicing connections, a gas compressor and conduit means arranged to deliver excess gas accumulation-in said container to said system at a point'on the upstream side of said pressure regulating means, and means responsive to pressure in said system for controlling the operation of said pumping means to maintain a pre-' determined pressure'in the system in advance of said regulatingmeans.

22. In a system for converting a liquefied gas into a vapor for industrial use, the combination with a heat insulated container having an inner vessel adapted for holding a supply of said liq uefied gas, of a gas consuming system including service connections and heating means, pressure building means including a heating coil connected to said vessel at points both above and below the normal liquid level therein, pumping means and fiuid conduits for supplying gas maing a boiling point temperature at atmospheric pressure materially less than 233 K., which comprises maintaining a supply or such gas matephase from the accumulation thereof within said 10 container when said gas phase has attained a pressure of a selected highwalue, elevating the pressure of said withdrawn gas phase to at least a predetermined service value, and continuing such withdrawal of gas phase to reduce the pressure of the gas phase in said container, and

stopping the withdrawal of said gas phase when aselected low value of the pressure of the gas phase being withdrawn is attained.

LYMAN A. BLISS. ODD A. HANSEN. 

